library(shiny)

ui <- fluidPage(

   mainPanel(

     actionButton("previous_q",
                  "Previous"),
     actionButton("next_q",
                  "Next"),
     selectInput("jump",
                 "Jump to Question",
                 choices = 1:10),
     textOutput("selected")

   )
)

server <- function(input, output) {

  # Select based on "Previous" and "Next" buttons -------

  selected <- reactiveVal(1)

  observeEvent(input$previous_q, {

    newSelection <- selected() - 1
    selected(newSelection)

  })

  observeEvent(input$next_q, {

    newSelection <- selected() + 1
    selected(newSelection)

  })

  # Jump to selection (COMMENTED OUT SO APP DOESN'T CRASH) ----------------

  #observeEvent(input$jump, {

    #newSelection <- input$jump
    #selected(newSelection)

  #})

  # Display selected

  output$selected <- renderText({
    paste(selected())
  })
}

shinyApp(ui = ui, server = server)

observeEvent(input$jump, {

    newSelection <- as.integer(input$jump)
    selected(newSelection)

  })